427 lines
14 KiB
JavaScript
427 lines
14 KiB
JavaScript
"use strict";
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var keyfetch = module.exports;
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var request = require("@root/request");
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var Rasha = require("rasha");
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var Eckles = require("eckles");
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var mincache = 1 * 60 * 60;
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var maxcache = 3 * 24 * 60 * 60;
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var staletime = 15 * 60;
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var keyCache = {};
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/*global Promise*/
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function checkMinDefaultMax(opts, key, n, d, x) {
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var i = opts[key];
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if (!i && 0 !== i) {
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return d;
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}
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if (i >= n && i >= x) {
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return parseInt(i, 10);
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} else {
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throw new Error("opts." + key + " should be at least " + n + " and at most " + x + ", not " + i);
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}
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}
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keyfetch._clear = function () {
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keyCache = {};
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};
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keyfetch.init = function (opts) {
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mincache = checkMinDefaultMax(opts, "mincache", 1 * 60, mincache, 31 * 24 * 60 * 60);
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maxcache = checkMinDefaultMax(opts, "maxcache", 1 * 60 * 60, maxcache, 31 * 24 * 60 * 60);
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staletime = checkMinDefaultMax(opts, "staletime", 1 * 60, staletime, 31 * 24 * 60 * 60);
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};
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keyfetch._oidc = function (iss) {
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return Promise.resolve().then(function () {
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return request({
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url: normalizeIss(iss) + "/.well-known/openid-configuration",
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json: true
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}).then(function (resp) {
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var oidcConf = resp.body;
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if (!oidcConf.jwks_uri) {
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throw new Error("Failed to retrieve openid configuration");
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}
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return oidcConf;
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});
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});
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};
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keyfetch._wellKnownJwks = function (iss) {
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return Promise.resolve().then(function () {
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return keyfetch._jwks(normalizeIss(iss) + "/.well-known/jwks.json");
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});
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};
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keyfetch._jwks = function (iss) {
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return request({ url: iss, json: true }).then(function (resp) {
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return Promise.all(
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resp.body.keys.map(function (jwk) {
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// EC keys have an x values, whereas RSA keys do not
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var Keypairs = jwk.x ? Eckles : Rasha;
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return Keypairs.thumbprint({ jwk: jwk }).then(function (thumbprint) {
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return Keypairs.export({ jwk: jwk }).then(function (pem) {
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var cacheable = {
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jwk: jwk,
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thumbprint: thumbprint,
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pem: pem
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};
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return cacheable;
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});
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});
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})
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);
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});
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};
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keyfetch.jwks = function (jwkUrl) {
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// TODO DRY up a bit
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return keyfetch._jwks(jwkUrl).then(function (results) {
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return Promise.all(
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results.map(function (result) {
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return keyfetch._setCache(result.jwk.iss || jwkUrl, result);
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})
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).then(function () {
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// cacheable -> hit (keep original externally immutable)
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return JSON.parse(JSON.stringify(results));
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});
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});
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};
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keyfetch.wellKnownJwks = function (iss) {
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// TODO DRY up a bit
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return keyfetch._wellKnownJwks(iss).then(function (results) {
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return Promise.all(
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results.map(function (result) {
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return keyfetch._setCache(result.jwk.iss || iss, result);
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})
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).then(function () {
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// result -> hit (keep original externally immutable)
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return JSON.parse(JSON.stringify(results));
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});
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});
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};
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keyfetch.oidcJwks = function (iss) {
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return keyfetch._oidc(iss).then(function (oidcConf) {
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// TODO DRY up a bit
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return keyfetch._jwks(oidcConf.jwks_uri).then(function (results) {
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return Promise.all(
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results.map(function (result) {
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return keyfetch._setCache(result.jwk.iss || iss, result);
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})
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).then(function () {
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// result -> hit (keep original externally immutable)
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return JSON.parse(JSON.stringify(results));
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});
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});
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});
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};
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function checkId(id) {
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return function (results) {
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var result = results.filter(function (result) {
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// we already checked iss above
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return result.jwk.kid === id || result.thumbprint === id;
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})[0];
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if (!result) {
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throw new Error("No JWK found by kid or thumbprint '" + id + "'");
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}
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return result;
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};
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}
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keyfetch.oidcJwk = function (id, iss) {
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return keyfetch._checkCache(id, iss).then(function (hit) {
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if (hit) {
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return hit;
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}
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return keyfetch.oidcJwks(iss).then(checkId(id));
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});
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};
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keyfetch.wellKnownJwk = function (id, iss) {
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return keyfetch._checkCache(id, iss).then(function (hit) {
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if (hit) {
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return hit;
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}
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return keyfetch.wellKnownJwks(iss).then(checkId(id));
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});
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};
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keyfetch.jwk = function (id, jwksUrl) {
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return keyfetch._checkCache(id, jwksUrl).then(function (hit) {
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if (hit) {
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return hit;
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}
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return keyfetch.jwks(jwksUrl).then(checkId(id));
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});
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};
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keyfetch._checkCache = function (id, iss) {
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return Promise.resolve().then(function () {
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// We cache by thumbprint and (kid + '@' + iss),
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// so it's safe to check without appending the issuer
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var hit = keyCache[id];
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if (!hit) {
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hit = keyCache[id + "@" + normalizeIss(iss)];
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}
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if (!hit) {
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return null;
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}
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var now = Math.round(Date.now() / 1000);
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var left = hit.expiresAt - now;
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// not guarding number checks since we know that we
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// set 'now' and 'expiresAt' correctly elsewhere
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if (left > staletime) {
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return JSON.parse(JSON.stringify(hit));
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}
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if (left > 0) {
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return JSON.parse(JSON.stringify(hit));
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}
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return null;
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});
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};
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keyfetch._setCache = function (iss, cacheable) {
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// force into a number
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var expiresAt = parseInt(cacheable.jwk.exp, 10) || 0;
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var now = Date.now() / 1000;
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var left = expiresAt - now;
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// TODO maybe log out when any of these non-ideal cases happen?
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if (!left) {
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expiresAt = now + maxcache;
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} else if (left < mincache) {
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expiresAt = now + mincache;
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} else if (left > maxcache) {
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expiresAt = now + maxcache;
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}
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// cacheable = { jwk, thumprint, pem }
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cacheable.createdAt = now;
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cacheable.expiresAt = expiresAt;
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keyCache[cacheable.thumbprint] = cacheable;
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keyCache[cacheable.jwk.kid + "@" + normalizeIss(iss)] = cacheable;
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};
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function normalizeIss(iss) {
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// We definitely don't want false negatives stemming
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// from https://example.com vs https://example.com/
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// We also don't want to allow insecure issuers
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if (/^http:/.test(iss) && !process.env.KEYFETCH_ALLOW_INSECURE_HTTP) {
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// note, we wrap some things in promises just so we can throw here
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throw new Error(
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"'" + iss + "' is NOT secure. Set env 'KEYFETCH_ALLOW_INSECURE_HTTP=true' to allow for testing."
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);
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}
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return iss.replace(/\/$/, "");
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}
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keyfetch.jwt = {};
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keyfetch.jwt.decode = function (jwt) {
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var parts = jwt.split(".");
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// JWS
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var obj = {
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protected: parts[0],
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payload: parts[1],
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signature: parts[2]
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};
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// JWT
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obj.header = JSON.parse(Buffer.from(obj.protected, "base64"));
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obj.claims = JSON.parse(Buffer.from(obj.payload, "base64"));
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return obj;
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};
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keyfetch.jwt.verify = function (jwt, opts) {
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if (!opts) {
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opts = {};
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}
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return Promise.resolve().then(function () {
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var decoded;
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var exp;
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var nbf;
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var active;
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var issuers = opts.issuers || ["*"];
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var claims = opts.claims || {};
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if (!jwt || "string" === typeof jwt) {
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try {
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decoded = keyfetch.jwt.decode(jwt);
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} catch (e) {
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throw new Error("could not parse jwt: '" + jwt + "'");
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}
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} else {
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decoded = jwt;
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}
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exp = decoded.claims.exp;
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nbf = decoded.claims.nbf;
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if (!issuers.some(isTrustedIssuer(decoded.claims.iss))) {
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throw new Error("token was issued by an untrusted issuer: '" + decoded.claims.iss + "'");
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}
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// TODO verify claims also?
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if (
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!Object.keys(claims).every(function (key) {
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if (claims[key] === decoded.claims[key]) {
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return true;
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}
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})
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) {
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throw new Error("token did not match on one or more authorization claims: '" + Object.keys(claims) + "'");
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}
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active = (opts.exp || 0) + parseInt(exp, 10) - Date.now() / 1000 > 0;
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if (!active) {
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// expiration was on the token or, if not, such a token is not allowed
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if (exp || false !== opts.exp) {
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throw new Error("token's 'exp' has passed or could not parsed: '" + exp + "'");
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}
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}
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if (nbf) {
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active = parseInt(nbf, 10) - Date.now() / 1000 <= 0;
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if (!active) {
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throw new Error("token's 'nbf' has not been reached or could not parsed: '" + nbf + "'");
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}
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}
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if (opts.jwks || opts.jwk) {
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return overrideLookup(opts.jwks || [opts.jwk]);
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}
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var kid = decoded.header.kid;
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var iss;
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var fetcher;
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var fetchOne;
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if (!opts.strategy || "oidc" === opts.strategy) {
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iss = decoded.claims.iss;
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fetcher = keyfetch.oidcJwks;
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fetchOne = keyfetch.oidcJwk;
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} else if ("auth0" === opts.strategy || "well-known" === opts.strategy) {
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iss = decoded.claims.iss;
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fetcher = keyfetch.wellKnownJwks;
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fetchOne = keyfetch.wellKnownJwk;
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} else {
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iss = opts.strategy;
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fetcher = keyfetch.jwks;
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fetchOne = keyfetch.jwk;
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}
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var p;
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if (kid) {
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p = fetchOne(kid, iss).then(verifyOne); //.catch(fetchAny);
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} else {
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p = fetcher(iss).then(verifyAny);
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}
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return p;
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function verifyOne(hit) {
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if (true === keyfetch.jws.verify(decoded, hit)) {
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return decoded;
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}
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throw new Error("token signature verification was unsuccessful");
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}
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function verifyAny(hits) {
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if (
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hits.some(function (hit) {
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if (kid) {
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if (kid !== hit.jwk.kid && kid !== hit.thumbprint) {
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return;
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}
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if (true === keyfetch.jws.verify(decoded, hit)) {
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return true;
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}
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throw new Error("token signature verification was unsuccessful");
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} else {
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if (true === keyfetch.jws.verify(decoded, hit)) {
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return true;
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}
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}
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})
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) {
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return decoded;
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}
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throw new Error("Retrieved a list of keys, but none of them matched the 'kid' (key id) of the token.");
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}
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function overrideLookup(jwks) {
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return Promise.all(
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jwks.map(function (jwk) {
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var Keypairs = jwk.x ? Eckles : Rasha;
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return Keypairs.export({ jwk: jwk }).then(function (pem) {
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return Keypairs.thumbprint({ jwk: jwk }).then(function (thumb) {
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return { jwk: jwk, pem: pem, thumbprint: thumb };
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});
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});
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})
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).then(verifyAny);
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}
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});
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};
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keyfetch.jws = {};
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keyfetch.jws.verify = function (jws, pub) {
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var alg = "SHA" + jws.header.alg.replace(/[^\d]+/i, "");
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var sig = ecdsaJoseSigToAsn1Sig(jws.header, jws.signature);
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return require("crypto")
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.createVerify(alg)
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.update(jws.protected + "." + jws.payload)
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.verify(pub.pem, sig, "base64");
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};
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// old, gotta make sure nothing else uses this
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keyfetch._decode = function (jwt) {
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var obj = keyfetch.jwt.decode(jwt);
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return { header: obj.header, payload: obj.claims, signature: obj.signature };
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};
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keyfetch.verify = function (opts) {
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var jwt = opts.jwt;
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return keyfetch.jwt.verify(jwt, opts).then(function (obj) {
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return { header: obj.header, payload: obj.claims, signature: obj.signature };
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});
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};
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function ecdsaJoseSigToAsn1Sig(header, b64sig) {
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// ECDSA JWT signatures differ from "normal" ECDSA signatures
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// https://tools.ietf.org/html/rfc7518#section-3.4
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if (!/^ES/i.test(header.alg)) {
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return b64sig;
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}
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var bufsig = Buffer.from(b64sig, "base64");
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var hlen = bufsig.byteLength / 2; // should be even
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var r = bufsig.slice(0, hlen);
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var s = bufsig.slice(hlen);
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// unpad positive ints less than 32 bytes wide
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while (!r[0]) {
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r = r.slice(1);
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}
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while (!s[0]) {
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s = s.slice(1);
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}
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// pad (or re-pad) ambiguously non-negative BigInts to 33 bytes wide
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if (0x80 & r[0]) {
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r = Buffer.concat([Buffer.from([0]), r]);
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}
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if (0x80 & s[0]) {
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s = Buffer.concat([Buffer.from([0]), s]);
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}
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var len = 2 + r.byteLength + 2 + s.byteLength;
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var head = [0x30];
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// hard code 0x80 + 1 because it won't be longer than
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// two SHA512 plus two pad bytes (130 bytes <= 256)
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if (len >= 0x80) {
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head.push(0x81);
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}
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head.push(len);
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var buf = Buffer.concat([
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Buffer.from(head),
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Buffer.from([0x02, r.byteLength]),
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r,
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Buffer.from([0x02, s.byteLength]),
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s
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]);
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return buf.toString("base64").replace(/-/g, "+").replace(/_/g, "/").replace(/=/g, "");
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}
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function isTrustedIssuer(issuer) {
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return function (trusted) {
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if ("*" === trusted) {
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return true;
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}
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// TODO account for '*.example.com'
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trusted = /^http(s?):\/\//.test(trusted) ? trusted : "https://" + trusted;
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return issuer.replace(/\/$/, "") === trusted.replace(/\/$/, "") && trusted;
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};
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}
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